The present invention relates to a filter, a fluidic member, a sample separation device, and a method of manufacturing a filter.
In liquid chromatography, a fluidic sample and an eluent (liquid mobile phase) may be pumped, by a piston pump, through conduits and a column in which separation of sample components takes place. In a sample loop, the sample may be injected into a fluidic path by a mechanically drivable needle. The drivable needle is controllable to be moved out of a seat of the sample loop into a vial to receive a fluid and back from the vial into the seat. The column may comprise a material which is capable of separating different components of the fluidic analyte. Such a material, so-called beads, which may comprise silica gel, may be filled into a column tube which may be connected downstream to other components, such as a detector, a fractioner, a waste, etc., by conduits.
In such and other fluidic measurement devices, debris can be unintentionally introduced in the processed fluid, for instance due to abrasion of a seal in a piston chamber of a pump, abrasion of a rotatable fluidic valve during switching, solid matter in the matrix of the sample, etc. Hence, filters may be introduced at certain positions within the flow path. Specific filters called frits may be made of a sintered material having pores or internal gaps allowing fluid to pass the filter but preventing debris particles from passing the filter.
EP 0,231,432, WO 93/11862, U.S. Pat. Nos. 5,304,487 5,985,164, US 2007/199877 disclose various filter concepts.
U.S. Pat. No. 7,645,383 discloses a microstructured filter having an inlet for unfiltered fluid, an outlet for filtered fluid, a plurality of projections, which form at least one row in a mutually juxtaposed relationship across the filter, that project out of a base plate and are an integral component of the base plate, a plurality of passages between the projections, and a cover plate which is securable to the base plate to cover the projections and the passages. The passages form a plurality of through paths from the inlet to the outlet. The inlet includes an elongate inlet slot for the unfiltered fluid that extends over approximately the entire filter width and is approximately as high as the projection on the outlet side of the filter.
US 2001/047966 discloses a method of isolating cell components, such as nucleic acids, from natural sources by filtering a sample of the digested natural sources such as cells or cell fragments. The method is characterized in that the sample is passed through a filter, the pore size of which decreases in the direction of flow of the sample through the filter.
However, conventional filters may suffer from clogging or plugging when a certain amount of debris has been loaded onto the filter. This may result in an undesired blockage of fluid flow. In case of partly blockage the pressure drop may increase to a level, at which such filters may break due to mechanical forces.